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Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces

Description: From Introduction: "The experiments in high-speed flow showed that an intense, high-frequency acoustic radiation is an essential feature of the problem. Consequently, a study of the acoustic field (involving schlieren observations and frequency and intensity measurements) was undertaken. This report presents the salient features of the study, which was mainly exploratory."
Date: August 1955
Creator: Krishnamurty, K.
open access

Acoustic, thrust, and drag characteristics of several full-scale noise suppressors for turbojet engines

Description: From Introduction: " Considerable analytical and experimental research has been done to find means of reducing the noise levels of the turbojet transports. Noise levels can be decreased by engine redesign to reduce the jet-exit velocity (ref. 1), proper flight-climb techniques (ref. 2), and the use of noise-suppression exhaust nozzles (refs. 3 to 5). The present report is concerned with the last method."
Date: April 1958
Creator: Ciepluch, Carl C.; North, Warren J.; Coles, Willard D. & Antl, Robert J.
open access

Adaptation of aeronautical engines to high altitude flying

Description: Report discussing Issues and techniques relative to the adaptation of aircraft engines to high altitude flight. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2.… more
Date: May 1923
Creator: Kutzbach, K.
open access

Adaptor for Measuring Principal Strains With Tuckerman Strain Gage

Description: Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error … more
Date: June 1943
Creator: McPherson, A. E.
open access

Additional Static and Fatigue Tests of High-Strength Aluminum-Alloy Bolted Joints

Description: From Introduction: "Early in 1951 the National Advisory Committee for Aeronautics published, as Technical Note 2276 (ref. 1), a report by the Aluminum Research Laboratories of the Aluminum Company of America on the results of static and fatigue tests of high-strength aluminum alloy monobloc specimens and bolted joints. In view of special interest shown by several aircraft companies, certain expansions of the test program were undertaken by the Aluminum Research Laboratories and are reported her… more
Date: July 1954
Creator: Hartmann, E. C.; Holt, Marshall & Eaton, I. D.
open access

Adhesion of Ice in Its Relation to the De-Icing of Airplanes

Description: From Summary: "The various possible means of preventing ice adhesion on airplane surfaces are critically reviewed. Results are presented of tests of the adhesives forces between ice and various solid and liquid forces. It is concluded that the de-icing of airplane wings by heat from engine exhaust shows sufficient promise to warrant full-scale tests. For propellers, at least, and possibly for certain small areas such as windshields, radio masts, etc. the use of de-icing or adhesion-preventing l… more
Date: August 1939
Creator: Rothrick, A. M. & Selden, R. F.
open access

Advantages of Oxide Films as Bases for Aluminum Pigmented Surface Coatings for Aluminum Alloys

Description: Report discussing both laboratory and weather-exposure corrosion tests showed conclusively that the protection afforded by aluminum pigmented spar varnish coatings applied to previously anodized aluminum surfaces was greatly superior to that afforded by the same coatings applied to surfaces which had simply been cleaned free from grease and not anodized.
Date: November 1931
Creator: Buzzard, R. W. & Mutchler, W. H.
open access

The Aerodynamic Analysis of the Gyroplane Rotating-Wing System

Description: "An aerodynamic analysis of the gyroplane rotating-wing system is presented herein. This system consists of a freely rotating rotor in which opposite blades are rigidly connected and allowed to rotate or feather freely about their span axis. Equations have been derived for the lift, the lift-drag ratio, the angle of attack, the feathering angles, and the rolling and pitching moments of a gyroplane rotor in terms of its basic parameters" (p. 1).
Date: March 1934
Creator: Wheatley, John B.
open access

Aerodynamic characteristics and flying qualities of a tailless triangular-wing airplane configuration as obtained from flights of rocket-propelled models at transonic and supersonic speeds

Description: Report discussing a flight investigation of rocket-powered models of a tailless triangular-wing airplane configuration was made through the transonic and low supersonic speed range at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. An analysis of the aerodynamic coefficients, stability derivatives, and flying qualities based on the results obtained from the successful flight tests of three models is presented.
Date: November 1956
Creator: Mitcham, Grady L.; Stevens, Joseph E. & Norris, Harry P.
open access

Aerodynamic characteristics at Reynolds numbers of 3.0 x 10(exp 6) and 6.0 x 10(exp 6) of three airfoil sections formed by cutting off various amounts from the rear portion of the NACA 0012 airfoil section

Description: Report presenting an investigation of the two-dimensional aerodynamic characteristics of three airfoil sections formed by removing various portions of the original chord from the trailing edge of the NACA 0012 airfoil section. Results regarding lift, drag, and pitching moment and aerodynamic center are provided.
Date: April 1950
Creator: Smith, Hamilton A. & Schaefer, Raymond F.
open access

Aerodynamic characteristics of 15 NACA airfoil sections at seven Reynolds numbers from 0.7 x 10(exp 6) to 9.0 x 10(exp 6)

Description: Report presenting an investigation of the two-dimensional aerodynamic characteristics of 15 NACA airfoils at four Reynolds numbers. The results indicate that the drag coefficient at the design lift coefficient and the maximum lift coefficient are the most important aerodynamic characteristics and are most affected by Reynolds number changes.
Date: October 1949
Creator: Loftin, Laurence K., Jr. & Smith, Hamilton A.
open access

Aerodynamic Characteristics of a Circular Cylinder at Mach Number 6.86 and Angles of Attack Up to 90 Degrees

Description: "Pressure-distribution and force tests of a circular cylinder have been made in the Langley 11-inch hypersonic tunnel at a Mach number of 6.88, a Reynolds number of 129,000, and angles of attack up to 90 degrees. The results are compared with the hypersonic approximation of Grimminger, Williams, and Young and a simple modification of the Newtonian flow theory. An evaluation of the crossflow theory is made through comparison of present results with available crossflow Mach number drag coefficien… more
Date: January 1957
Creator: Penland, Jim A.
open access

The Aerodynamic Characteristics of a Model Wing Having a Split Flap Deflected Downward and Moved to the Rear

Description: "Tests were made on a model wing with three different sized split trailing-edged flaps, in the NACA 7 by 10 foot wind tunnel. The flaps were formed of the lower rear portion of the wing and were rotated downward about axes at their front edges. The lift, drag, and center of pressure were measured with the axis in its original position and also with it moved back in even steps to the trailing edge of the main wing, giving in effect an increase in area. The split flaps when deflected about their … more
Date: May 1932
Creator: Weick, Fred E. & Harris, Thomas A.
open access

Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes

Description: From Introduction: "The results of one phase of this investigation, presented in reference 1, have indicated that hull drag can be reduced without causing large changes in aerodynamic stability and hydrodynamic performance by the use of high length-beam ratios. Another phase of the investigation, reference 2, indicated that hulls of the deep-step planning-tail type have much lower air drag than the conventional type of hull and about the same aerodynamic stability; tank tests, reference 3, have… more
Date: June 1952
Creator: Riebe, John M. & Naeseth, Rodger L.
open access

Aerodynamic Characteristics of a Small-Scale Shrouded Propeller at Angles of Attack From 0 to 90 Degrees

Description: Note presenting an investigation to determine the effects of airspeed and angle of attack on the lift, drag, and pitching moment of a shrouded-propeller model with a shroud length of about two-thirds the propeller diameter over an angle of attack from 0 to 90 degrees. Tests were made of the complete model with the propeller operating and also of the shroud and motor combination with the propeller removed.
Date: November 1955
Creator: Parlett, Lysle P.
open access

Aerodynamic characteristics of a two-blade NACA 10-(3)(062)-045 propeller and of a two-blade NACA 10-(3)(08)-045 propeller

Description: Report discussing characteristics are given for the two-blade NACA 10-(3)(062)-045 propeller and for the two-blade NACA 10-(3)(08)-045 propeller over a range of advance ratio from 0.5 to 3.8, through a blade-angle range from 20 degrees to 55 degrees measured at the 0.75 radius. Maximum efficiencies of the order of 91.5 to 92 percent were obtained for the propellers. The propeller with the thinner airfoil sections over the outboard portion of the blades, the NACA 10-(3)(062)-045 propeller, had l… more
Date: January 1953
Creator: Solomon, William
open access

The Aerodynamic Characteristics of Airfoils as Affected by Surface Roughness

Description: "The effect on airfoil characteristics of surface roughness of varying degrees and types at different locations on an airfoil was investigated at high values of the Reynolds number in a variable density wind tunnel. Tests were made on a number of National Advisory Committee for Aeronautics (NACA) 0012 airfoil models on which the nature of the surface was varied from a rough to a very smooth finish. The effect on the airfoil characteristics of varying the location of a rough area in the region o… more
Date: April 1933
Creator: Hooker, Ray W.
open access

The aerodynamic characteristics of an aspect-ratio-20 wing having thick airfoil sections and employing boundary-layer control by suction

Description: Report presenting an investigation to study the aerodynamic characteristics of an aspect-ratio-20 wing with thick airfoil sections and employing boundary-layer control by suction. The results include the effects of varying suction flow rate, suction-slot configuration, wing surface condition, flap deflection, and Mach number are provided.
Date: August 1953
Creator: Cocke, Bennie W., Jr.; Fink, Marvin P. & Gottlieb, Stanley M.
open access

Aerodynamic Characteristics of Damping Screens

Description: From Summary: "The experimental investigation of damping screens described herein was undertaken primarily to test theories of the effects of damping screens and to obtain information on the performance of screens in oblique flow. The characteristics investigated include the damping of longitudinal and lateral components of turbulence, the effect of screens on scale, the conditions for the production of turbulence and eddies by screens, and the damping of spatial variations of mean speed."
Date: January 1950
Creator: Schubauer, G. B.; Spangenberg, W. G. & Klebanoff, P. S.
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